Sole for footwear capable to adapt itself to shape or to deformations of the user&#39;s foot

ABSTRACT

Sole for footwear capable to adapt itself to shape or to deformations of the user&#39;s foot includes a first layer on which, in the part at the forefoot, at least a first cut is made, passing approximately in a longitudinal direction of the sole and proximal to the first lateral edge of the sole. A second layer is attached to the first layer, on which a second through cut is made, approximately according to a longitudinal direction of the sole, arranged proximal to a second lateral edge of the sole. A double-sided adhesive layer is attached to the first layer so as to be interposed between the first and second layers and to overlap the lips of the second cut. A-protective film is attached on a face of the double-sided adhesive tape in contact with said second layer, wherein the film projects outside the sole through the first cut.

FIELD OF THE INVENTION

The present invention relates to the sector of footwear capable to adapt itself to shape or to deformations of the user's foot.

BACKGROUND OF THE INVENTION

In the prior art, it is known in the footwear sector that purchasers of shoes often find it difficult to put them on due to problems that may be of various kinds, including:

-   -   differences between the right foot and the left foot;     -   joint pain;     -   increased foot size due to obesity;     -   bunions;     -   hammer toes.

These difficulties arise when the shoe can no longer expand horizontally, resulting in loss of user comfort.

It is well known that, unlike the length, which is a parameter that can be chosen when purchasing a shoe, the width of the shoe, and therefore of the sole on which it is mounted, is not an element that can be chosen.

In the state of the art, an attempt has been made to overcome the disadvantage of non-variability of width by creating:

-   -   different forms for the same size, which are models on which the         upper of a shoe is stretched assuming its conformation—the shoes         thus obtained, however, have the drawback of having a standard         fit without the possibility of customisation by the user;     -   different types of moulds having different forms of assembly         which, at the same time, however, entail a rise in the         manufacturing costs of the footwear.

SUMMARY OF THE INVENTION

Purpose of the present invention is to devise a sole for footwear capable of widening transversely to the development of the sole, maintaining this configuration after e relative foot is extracted from the footwear.

Another purpose of the present invention is to devise a sole for footwear the thickness of which has no manufacturing constraints such as those of the footwear of the prior art, thus making it a sole adaptable to any type of footwear.

A no less important purpose of the present invention is to devise a sole for footwear that is able to solve footwear problems arising from foot malformations (bunion, hammer toes etc.) much more effectively and at a much wider level than the footwear known in the state of the art.

The basic idea of the present invention is to provide at least the front portion of the sole of a shoe by means of two overlapping layers, of which a second layer, internal, intended to face a relative foot and a first layer, external, intended to face the ground. Each of the two layers has an approximately longitudinal cut. The first cut, relative to the first layer, is arranged proximal to a first lateral edge of the sole, while the second cut, relative to the second layer, is arranged proximal to a second lateral edge of the sole, opposite to the first.

In other words, the two cuts are mutually staggered.

Between the first and second layers a layer of double-sided adhesive is arranged, attached to the second layer and detached from the first layer by means of a folded film so that it can be extracted from the second cut.

The double-sided tape is arranged so that, when the film is removed, it sticks to both lips of the first cut, so as to prevent rapprochement between the lips. Thanks to the present invention, by inserting a foot inside the shoe equipped with the film, both the first and the second layer are free to expand transversely to the longitudinal development of the sole. While the foot is in the shoe, the extraction of the film causes the second layer to attach to the first by means of the double-sided tape, therefore, the lips of the second cut are no longer allowed to reciprocal rapprochement, so that the sole retains the acquired shape. Even the lips of the first cut remain dilated ensuring optimal comfort.

Preferably, the double-sided adhesive layer is made of waterproof material, so that the shoe can be put on even in case of rain without water penetrating inside.

According to another preferred embodiment of the invention, after the extraction of the film, the second cut is filled with a filling material, for example based on silicone, or polymer, sealing the sole of the shoe.

The dependent claims form an integral part of the present description.

BRIEF DESCRIPTIONS OF THE FIGURES

Further characteristics and advantages of the invention will be clear from the description of a preferred but not exclusive sole for footwear able to adapt to the conformation and to malformations of the foot according to the present patent application, illustrated by way of non-limiting example in the appended drawings, wherein:

FIG. 1 shows a top view of an example of an incomplete sole (1) for footwear, where on a tread (2) a double-sided adhesive layer (3) is provided at the forefoot having a protective film (8) folded on itself and then made to pass through a cut (4) made on the tread (2) itself;

FIG. 2 shows a top view of the example of FIG. 1 with a half sole (5) next to it having a cut (6) intended to be attached to the tread (2);

FIG. 3 shows in an axonometric view the sole (1) of the previous figures in which the half-sole (5) is glued on the tread (2);

FIG. 4 shows in an axonometric view the sole (1) of FIG. 3 with which an elastic layer (7) is attached which must be mounted on the footwear (not shown);

FIG. 5 shows a bottom view of the example of footwear according to any one of the previous figures, in which the protective film (8) of the double-sided adhesive layer (3) protrudes from the cut (4) of the tread (2).

DETAILED DESCRIPTION OF THE INVENTION

According to a preferred—but non-limiting—embodiment, the present invention relates to a sole (1) for footwear able to adapt to the conformation and to malformations of the foot, comprising:

-   -   a tread (2) on which, in the part at the forefoot, at least a         first cut (4) is made in the direction of the length in a         proximal position with respect to a first edge of the sole (1);     -   a double-sided adhesive layer (3) placed on the tread (2) and         having a protective film (8);     -   a half sole (5) intended to be attached to the tread (2) on         which a second cut (6) is made, positioned proximal to a second         edge of the sole (1), opposite to the first edge.

Looking at FIG. 2, it is understood that the half sole (5) has a shape similar to the front portion of the tread.

This shape, although rounded, recalls that of an isosceles trapezoid.

The first cut is made in order to facilitate the extraction of the protective film, while the second cut is made in order to facilitate the adaption of the sole to the shape of the foot.

In the figures it is seen that the two cuts are approximately parallel to the opposite lips of the isosceles trapezoid defined by the front portion of the sole. Nonetheless, the first cut can assume all intermediate angles and be perfectly aligned with the longitudinal direction of development X of the sole and arranged, for example, more centrally.

The second cut, although longitudinal in shape, can also be slightly curved to facilitate the adaptation of the half sole to the foot. Furthermore, it may be convenient to have the second cut in a more central position, while the first cut is closer to the edge of the sole.

What really matters is that the double-sided tape must be attached to the tread in order to fix the lips of the second cut to the tread when the protective film is removed.

Therefore, the double-sided adhesive layer overlaps the second cut and extends transversely to the longitudinal development direction X, towards the first cut, preferably up to its internal edge.

It is evident that it is considered as the internal lip of a cut, that lip that faces the other cut, while considering the external lip that faces towards the respective proximal edge of the sole.

It must also be clear that the half sole can also be a whole plant, i.e. a so-called insole, so as to cover the entire tread inside the shoe.

The cuts described above are through, i.e. for the entire thickness of the respective layers, i.e. the tread and the half sole.

These cuts can be angled with respect to the plane containing the sole, with an angle comprises between 45 and 90°.

With regard to the tread (2), the materials with which it can be made are those normally used in the state of the art, including:

-   -   E.V.A.—based microporous sheets;     -   rubber;     -   leather;     -   thunit.

The components of the sole (1) are preferably cut with a die or automatic cutting machine and, in the specific case of the tread (2), also making the first cut (4) for the insertion of the protective film (8) of the layer of double-sided tape (3). The shape of the cut (4) is conditioned by the design and aesthetics that will be given to the sole (1).

Alternatively to the materials listed above, the following can be used:

-   -   TR;     -   polyurethane;     -   TPU.

Such materials are generally used for molding.

Even with the aforementioned materials, the tread (2) is molded so as to carry the first cut (4).

The material for the realization of the half-sole (5) does not necessarily have to be the same as that of the tread (2).

In addition, the half-sole (5) does not necessarily have to be the same size as the tread (2), but may be larger or smaller as required.

The tread (2) can have a hollow part, in which the first cut (4) is made so as to provide for the insertion of the half plant (5) previously equipped with the second cut (6). Precisely for the construction methods of a cassette bottom, the dimensions of the half plant (5) are smaller and those of the tread (2).

Nonetheless, the shape of the half plant is similar, albeit smaller, than the shape of the front portion of the tread.

The half-sole (5) is made in the same way as the tread (2). Regardless of the material with which it is made, what must be kept unchanged is the type of cut (6) since it must be made “straight”, i.e. parallel to the longitudinal direction defined by the toe-heel connection line, in order to facilitate the opening of the same when the shoe is put on.

The double-sided adhesive layer (3) placed between the tread (2) and the half-sole (5) serves to secure said two parts at the moment in which the sole (1) has undergone the widening caused by the insertion of the foot into the shoe. In fact, when the footwear has adapted to the foot, ensuring perfect comfort, the double-sided adhesive layer (3) hitherto attached only to the tread (2) is freed from the relative protective film (8), also attaching to the half-sole (5), thereby obtaining the compaction of the sole (1).

The shape of the double-sided adhesive layer (3) is obtained by die-cutting or cutting and will be dictated, on one side, by the profile of the cut (4) on the tread (2); on the other it must exceed, according to a direction transverse to the longitudinal development direction X, by a few millimetres (about 4-6 mm), the second cut (6) of the half-sole (5) in order to block the position of the relative lips with respect to the tread. According to the longitudinal direction of development X, the double-sided tape must exceed the ends of the second cut (6) by 4-6 mm.

In other words, the double-sided adhesive layer extends between the first cut until it reaches and exceeds the second cut, when the half sole is attached to the tread in an operative configuration.

The double-sided adhesive layer thus made serves to ensure that, following the mutual removal of the lips of the second cut (6), it is able to constitute a barrier to the penetration of water into the sole.

To further improve the waterproofing of the tread, after removing the film, it is possible to inject in the first cut an adhesive paste capable of sealing the tread.

The material of the layer (3) is preferably a closed-cell, double-sided adhesive designed to ensure that it is waterproof, ensuring that the shoe is watertight and suitable for walking even on ground with pools of water or snow without these being able to penetrate inside.

As regards the protective film (8) of the double-sided adhesive layer (3), it is made of a die-cut silicone plastic film perforated to cover the face of the double sided layer in contact with the half sole and includes an extraction tab that extends for the transverse length of the double-sided layer crosses the tread and protrudes externally from it for 1-1.5 cm.

The film is attached to the double-sided adhesive starting from the edge of the same double-sided adhesive proximal to the first cut, folded on itself and inserted into the cut until it juts out from it.

The protective film (8) therefore has a transverse extension that is more than double compared to the double-sided adhesive layer (3). On one side, a flap of said protective film (8) is proximal to the cut (4) of the tread (2), while on the other side it must go 1-6 mm beyond the double-sided adhesive layer (3) so that, by pulling the extraction tongue on the tread (2), the protective film (8) unrolls, facilitating detachment from the double-sided adhesive layer (3). The protective film (8) is preferably made of siliconed plastic, in this way it is ensured that the adhesives that must be used in the assembly do not adhere to it, preventing its extraction.

The protective film (8) also facilitates the sliding between the half-sole (5) and the tread (2) and therefore their bonding during the phase of conformation of the sole to the foot, i.e. when the foot is inserted in the shoe and the protective film has not yet been extracted from it.

The upper is associated with the sole (1) to define the complete shoe, it can be shaped to wrap the foot right under the sole of the foot forming a tubular partially defined by an elastic layer (7) at least in correspondence with a portion that overlaps the second cut.

The purpose of the elastic layer (7) is to guarantee the enlargement of the upper when the shoe is put on, also ensuring that the upper itself adheres optimally to the foot.

The material of the elastic layer (7) is that normally available on the market and sold in elastic tapes.

It is important that:

-   -   in the positioning on the upper, the direction of extension of         the elastic layer (7) is transversal with respect to the         longitudinal development direction X;     -   when gluing the upper to the sole (1), the elastic layer (7) is         not glued for at least 2 cm from the lip of the second cut (6)         towards the centre of the half-sole (5).

A preferred method of assembling the sole (1) includes the following steps:

-   -   insertion of the protective film tab (8) inside the first cut         (4)     -   detachment of the original film from the face of the         double-sided adhesive layer (3) destined to contact the         half-sole (5)     -   attachment of the protective film (8) on the face of the         previously peeled double-sided adhesive layer,     -   folding of the protective film (8) on the lip between the second         cut (6) and the tongue itself;     -   peeling off the other side of the double-sided adhesive layer         (3) and attaching the double-sided adhesive layer so as to be         next to the internal lip of the first cut (4) so as not to         prevent the opening of the same first cut;     -   distribution of glue over the entire surface of the tread (2)         remained visible, that is, not covered by the protective film e     -   distribution of the same adhesive on the half-sole (5) leaving         out the area destined to overlap the protection film before and         the double-sided adhesive layer after removing the protection         film;     -   pressure union of the tread (2) with the half-sole (5) so as to         ensure that the two parts constitute a single block capable of         forming the sole (1).

The second cut (6) of the half-sole (5) and the first cut (4) of the tread (2) may have different embodiments, including:

-   -   the cut (4) of the tread (2) can be extended to the heel area,         ensuring a comfortable fit for both the forefoot and heel area;     -   in the event that a shoe is to be made with the wedge made of         rigid material, such as EVA, the second cut (6) can be made from         one side to the other dividing said half-sole (5) into two         parts;     -   in the event that a shoe is to be made in a rigid material, for         example a wedge, a very rigid tread can be provided, in which a         seat or box is made in which an elastic layer corresponding to         the first layer and a half-sole is accommodated, with the         relative cuts and locking system described above. In this case         the cut (6) of the half-sole (5) can be made by cutting said         half-sole (5) almost or for the entire longitudinal length.

As can be seen in the figures, the cuts are essentially inside the contour of the tread and half sola respectively.

The length of the cuts (4, 6) is proportional to the conformability that is intended to be given to the sole (1); said length is variable depending on the material used to make said sole.

The sole (1) is presented to the operator who assembles the shoe like a normal pre-trimmed sole or with a template welt. The only precaution that the operator where to have is to avoid making the elastic layer (7) adhere to the half sole around the second cut.

The materials and dimensions of the invention as described above, illustrated in the appended drawings and claimed below, may be any as required. In addition, all the details are replaceable with others technically equivalent, while remaining within the sphere of protection of this patent application. 

1. Sole for footwear capable to adapt itself to shape or to deformations of the user's foot, the sole for footwear comprising: a first layer on which, in a part at a forefoot, at least a first cut is made, passing approximately in a longitudinal direction of the sole and proximal to a first lateral edge of the sole; a second layer intended to be attached to the first layer, on which at least a second through cut is made, approximately according to a longitudinal direction of the sole, arranged proximal to a second lateral edge of the sole, opposite the first edge; a double-sided adhesive layer attached to said first layer so as to be interposed between the first and second layers and so as to overlap lips of the at least a second cut; and a protective film attached on a face of the double-sided adhesive tape in contact with said second layer, wherein the film projects outside the sole through said at least a first cut.
 2. Sole according to claim 1, wherein the first layer defines a tread of the sole and wherein the second layer defines a half-sole having a shape similar to the front portion of the first layer or it can define a whole plant so as to have a shape similar to the first layer.
 3. Sole according to claim 1, wherein an anterior portion of the sole has the shape of an isosceles trapezoid and wherein the first cut and the second cut are oriented according to an intermediate direction between said longitudinal direction and a direction parallel to the sides of the isosceles trapezoid and/or where said cuts are angled with respect to the plane containing the sole with an angle comprised between 45° and 90°.
 4. Sole for footwear according to claim 1, wherein the double-sided adhesive layer overlaps the second cut and extends transversely to the longitudinal axis, towards the first cut, preferably up to the inner lip of the latter.
 5. Sole for footwear according to claim 1, wherein the double-sided adhesive layer is preferably a closed cell double-sided tape.
 6. Sole according to claim 1, wherein the protective film of the double-sided adhesive layer: comprises a die-cut silicone plastic film; and is attached to the double-sided tape, covering its entire face intended to contact the second layer, starting from the edge of the same double sided tape proximal to the first cut, folded on itself and inserted in the first cut until it projects outwards from it.
 7. Sole according to claim 1, wherein at least one of said first and second cuts is inside the edge of a respective layer.
 8. Sole according to claim 1, wherein: the first cut is stretched up to the heel area; and/or the second cut is made from part to part by dividing the half sole into two parts.
 9. Sole according to claim 1, wherein the second layer is intended to be exposed externally to the shoe or exposed internally to the shoe with the first layer intended to be exposed externally to the shoe.
 10. Footwear comprising an upper and a sole according to claim
 1. 11. Method for assembling a sole according to claim 1, comprising the following steps: making said first and second layers and related first second cuts; inserting a portion of the protective film through the first cut to project outside the sole; detachment of an original film from a face of the double-sided adhesive layer intended to contact the second layer; attachment of the protective film on the face of the previously peeled double-sided adhesive layer; peeling off the other side of the double-sided adhesive layer and attaching the double-sided adhesive layer to the first layer so as to overlap the lips of the second cut when it is attached to the first layer, resulting in the protective film remaining folded on itself; distribution of glue over the entire surface of the first visible layer, that is, not covered by the protective film and distribution of the same glue on the second layer, leaving out an area intended to overlap the first protective film and the layer of double-sided adhesive after removing the protective film; and pressure union of the first layer with the second layer so as to form a sole. 